I found a leak at the cold water supply line of the Hot Water Heater, which is under the sink:
You can see the blue PEX line that is crimped to a brass fitting that elbows into a plastic 1/2" FIP. There are two or three problems. The first is the if you look closely, you can see where the fitting gouged the vinyl on the deck. During original installation, not enough clearance was provided, and the fitting took the load. Secondly, the stub coming out of the tank is a male pipe. You can see it is rusted, so I'm guessing it wasn't galvanized, but rather is black pipe. But also, according to plumbing and irrigation websites that discuss metal-to-plastic fittings, you should never connect metal male with plastic female...they claim it will always fail or leak. Instead, the connection should be the opposite, due to the taper of the threads. A typical explanation is given here.
To remedy, I decided to put in an galvanized street elbow at the rusted stub, because I did not want to risk breaking the stub-to-tank connection....I was afraid of damaging the tank. I then used Sharkbite press-on PEX fittings (at the tank, FIP-to-press-on) , including an 18" flex hose, to tie back into the blue PEX line. To get the elbow to turn, I had to cut a hole in the deck of the cabinet. I will make the same changes to the hot water side, but access is a little better there so I won't need the elbow, and no need for cutting the deck (which was tedious).
Incidentally, the plastic fitting was not cracked. The leak was between the brass and plastic.
You can see the blue PEX line that is crimped to a brass fitting that elbows into a plastic 1/2" FIP. There are two or three problems. The first is the if you look closely, you can see where the fitting gouged the vinyl on the deck. During original installation, not enough clearance was provided, and the fitting took the load. Secondly, the stub coming out of the tank is a male pipe. You can see it is rusted, so I'm guessing it wasn't galvanized, but rather is black pipe. But also, according to plumbing and irrigation websites that discuss metal-to-plastic fittings, you should never connect metal male with plastic female...they claim it will always fail or leak. Instead, the connection should be the opposite, due to the taper of the threads. A typical explanation is given here.
To remedy, I decided to put in an galvanized street elbow at the rusted stub, because I did not want to risk breaking the stub-to-tank connection....I was afraid of damaging the tank. I then used Sharkbite press-on PEX fittings (at the tank, FIP-to-press-on) , including an 18" flex hose, to tie back into the blue PEX line. To get the elbow to turn, I had to cut a hole in the deck of the cabinet. I will make the same changes to the hot water side, but access is a little better there so I won't need the elbow, and no need for cutting the deck (which was tedious).
Incidentally, the plastic fitting was not cracked. The leak was between the brass and plastic.
